title.
Honestly, not really. Just swallow and posture your tongue correctly, tongue chewing is not necessary. Furthermore, you can't really get the gum that far back where the soft palate is or you'd probably just swallow it. I can only see tongue chewing useful for serving as a reminder to mew, just as people chew on gum while concentrating or focusing without thinking about it. One problem for many people is when they start focusing on something they forget about mewing so maybe tongue chewing could help with that.